MeGUI

MeGUI is a free app based on ISO MPEG-4 that allows you to convert videos to multiple video and audio formats.

The interface can prove to be somewhat confusing at first, however it does have a one-click conversion function to make things easier for the uninitiated. While it may be more complicated than other, similar programs, the results are often much better, even more so when you consider that this is a free program.

By using AviSynth, the app offers a huge range of options for editing the videos, such as re-cutting, rotating, adding watermarks, adjusting the brightness or contrast, etc.

Whether you dare inexperienced but want better results than you get in more basic programs, or you really want to exploit all its possibilities to the full, this is one of the very best options currently available for converting videos.